Silent blocks are used, for example in the automobile industry, to reduce the generation of noise that can be transmitted to a vehicle interior. For example, silent blocks can be used for vibration insulation on steering lines, air-conditioning system lines, and vacuum lines, for example to insulate the lines when fastened to a body of the vehicle. Use of silent blocks in a vehicle suspension is disclosed, for example, in U.S. Pat. Nos. 7,293,787, 7,270,341, and 5,651,561. Use of silent blocks in disk brakes is disclosed in U.S. Pat. No. 7,156,212. Use of silent blocks in rack and pinion steering is disclosed in U.S. Pat. No. 6,749,040.
Silent blocks conventionally have a base plate received in a rubber block, as described, for example, in DE 3524791 A1, which discloses a rubber-metal buffer. The rubber-metal buffer has a rubber body with two connecting parts, each of which is connected to the rubber body. A thread-free bolt for fastening to associated components is provided on each of the two connecting parts. The base plate is surrounded laterally by a circumferential part.
Silent blocks are also disclosed in DE 3135043 A1, DE 3742585 C1, DE 4237428 A1 (which corresponds to U.S. Pat. No. 5,295,671), DE 202004010409 U1, DE 1727095 U, EP 0984197 B1, GB 602,256 (which corresponds to U.S. Pat. No. 2,465,790), U.S. Pat. No. 3,879,024 and U.S. Pat. No. 5,845,895.
EP 1526212 A2 (corresponding to U.S. Patent Publication No. 2005/081577) discloses a washing machine with feet having vibration-absorbing parts consisting of rubber. A first vibration-absorbing part is in contact with a standing surface. A second vibration-absorbing part is arranged higher than the first vibration-absorbing part with respect to the standing surface. The two vibration-absorbing parts are separated from one another by a groove.
Silent blocks in a round or angular configuration require additional tools for fastening to prevent the silent block from twisting and allow it to maintain its mounting position. It is possible, however, to provide the silent block or base plate with a device for increasing friction to counteract twisting during fastening (usually screwing). Friction can be increased by utilizing a profiled surface on a contact side of the base plate with a corresponding fastening component. For example, the contact side of the base plate could be scored to generate a tooth-like profile that penetrates, with an increasing fastening force, into a corresponding opposite side. However, this can cause the corresponding component to be damaged on its surface, which can in turn increase the risk of corrosion. The useful life of the corresponding component may consequently be reduced considerably.